1. Field of Invention
The present invention relates generally to the field of data and content distribution networks. More specifically, the present invention relates in one exemplary aspect to methods and apparatus for delivering programming content along with data via an optical fiber (e.g., fiber to the home or FTTH) network to a premises.
2. Description of Related Technology
FIG. 1 illustrates one exemplary implementation of a prior art headend architecture for providing content including e.g., broadcast, on-demand (OD), and pay-per-view (PPV) content. As shown, the headend architecture comprises various headend entities including a billing module, subscriber management system (SMS) and CPE configuration management module, cable-modem termination system (CMTS) and OOB system, as well as LAN(s) placing the various components in data communication with one another.
A key feature of this prior art implementation is the placement of a multiplexer-encrypter-modulator (MEM) at the headend. The MEM processes or conditions content received from the one or more file servers and/or VOD servers and/or real-time streaming video sources for transmission over the network. The MEM processes information so that it may be carried across multiple QAM channels. Thus, the headend must be adapted to acquire the information for the carried channels from various sources. Typically, the channels being delivered from the headend to the CPE (“downstream”) are multiplexed together in the headend at the MEM, and sent to neighborhood hubs via a variety of interposed network components. The aforementioned prior art MEM functionality may also be implemented at a network hub.
FIG. 2 illustrates an exemplary prior art “switched” network architecture (also referred to herein as a “broadcast switched architecture” (BSA)) for providing switched digital video or “SDV”. As illustrated, the headend contains switched broadcast control and media path functions these elements cooperate to control and feed, respectively, downstream or edge switching devices at the hub site which are used to selectively switch broadcast streams to various service groups.
Generally, packets associated with services are received by an edge switch device, and forwarded to an IP router The IP router examines the packets, and forwards packets intended for the local network to the edge switch. The edge switch forwards the packets received from the IP router to a headend-based or hub-based QAM modulator, which transmits the packets on one or more physical (QAM-modulated RF) channels to the CPE. Packets are transported across an optical IP network, typically using Gigabit or 10 Gigabit Ethernet. In the prior art, a single edge switch (or an off-the-shelf IP switch/router) device is typically utilized to provide SDV or BSA services to a plurality of user premises, each premises having one or more CPE therein.
In contrast to the hybridized networks of FIGS. 1 and 2, fiber-based data delivery networks are becoming increasingly prevalent. One such network, the Fiber-to-the-home or “FTTH”, network, delivers communications signals over optical fiber from the MSO switching equipment (at the network headend or distribution hub) all the way to a home, business, or other customer premises. The optical fiber in an FTTH network replaces existing copper infrastructure such as telephone wires and coaxial cable. FTTH provides higher bandwidth to consumers, thus enabling more robust video, internet and voice services than previously available in traditional coaxial cable and/or hybrid fiber coaxial cable (HFC) networks.
Various optical networks may be used to implement FTTH technologies. For example, a passive optical network (PON) such as an Ethernet PON (or EPON) may be utilized. A PON uses point-to-multipoint architecture in which unpowered optical splitters are used to enable a single optical fiber to serve multiple premises. This architecture reduces the amount of fiber and central office equipment required as compared to other, point-to-point architectures. Downstream signals are broadcast to each premises sharing a single fiber. Upstream signals are combined using a multiple access protocol, such as time division multiple access (TDMA). Alternatively, the FTTP technology may be made to work over any native IP access system.
Connecting a premises directly to fiber optic cable enables enormous improvements in the bandwidth that can be provided to consumers. For example, current fiber optic technology can provide two-way transmission speeds of up to 10 Gigabits per second Presently, FTTH technologies are deployed primarily in business or commercial settings. However, the aforementioned bandwidth increase and other advantages associated with fiber delivery are desirable in residential as well as other settings.
A major stumbling block in the progression towards implementing a fully FTTH optical network architecture in managed network scenarios (e.g., for a terrestrial cable television provider) is that legacy systems are currently in use by a majority of the network's subscribers. Conventional set top boxes (STBs) receive and transmit information related to video services via coaxial cable. The coaxial cable, in turn, is then in communication with fiber optic cables in a hybrid fiber-coax (HFC) system. This architecture is utilized to provide a two-way communication path between the set top box and the data service hub. Such two-way communication is necessary for e.g., authorizing a subscriber to view certain programs and channels. For example, on-demand (OD) and pay-per-view (PPV) systems utilize two-way communications between the STB and headend OD/PPV entities. Likewise, in a switched digital video (SDV) system (also referred to as a “broadcast switched architecture” or BSA), requests for content are transmitted upstream to an SDV server from the STB. Traditionally, FTTH systems do not provide a return path for communications upstream from the STB to the network. Generally, the return paths in an FTTH system comprise only fiber optic cables that propagate digital data signals, as opposed to analog RF signals which are required for communication in from the STB back to the network.
Additionally, conventional FTTH systems may suffer the following deficiencies with respect to operation of legacy devices: (i) FTTH may not support the encryption formats which are generally used in legacy devices, (ii) FTTH may not support the “always-on” full carriage of the entire program lineup (and doing so would exceed the capacity of the FTTH system), and (iii) FTTH does not currently have an existing program guide.
Based on the foregoing, what is needed are apparatus and methods for providing FTTH (or other optically based) services in a manner which allows for the use of both legacy user devices as well as non-legacy devices, while also addressing the need for upstream communication from the user devices to the network (such as to provide OD, PPV and SDV functionalities). Such methods and apparatus would also ideally be transparent to the network and the legacy and non-legacy STB.